1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a magnetic recording medium having a magnetic layer on which information is recorded, wherein the magnetic layer has a plurality of magnetic layers including thin film type magnetic layers and pattern-shaped magnetic layers, and a method of manufacturing the same.
2. Description of the Related Art
Due to their characteristics such as large information storing capacity and high access speed, hard disc drives (HDDs) that have a magnetic recording medium are used as the main information memory devices in various digital apparatuses. The storing capacity of the magnetic recording medium is determined by a track density (tracks per inch, TPI) in a radial direction of a disc and a linear density (bits per inch, BPI) in a rotational direction of the disc.
Consecutive magnetic recording media, that is, magnetic recording media in which the bits are not physically separated, have a limit in increasing the TPI and BPI by reducing the size of bits or the pitch of the tracks. This is because, if the size of bits or the pitch of the tracks is reduced below a predetermined limit, noise increases and the recording stability is rapidly reduced due to mutual magnetic interference between adjacent bits.
In order to address the above problems, patterned media such as discrete track media (DTM) and bit patterned media (BPM), in which tracks and bits are physically separated by forming the bits and the tracks in a pattern, have been developed. In the DTM, the tracks form concentric circles and are separated from each other in a radial direction of the disc, and in the BPM, the bits which are unit recording regions are separated in an island shape. The separating regions between the patterned tracks and the bits are emptied or filled with a non-magnetic material.
Magnetic recording media formed in the patterned shape may have high recording density since there is no interference between tracks or adjacent bits which are unit bit regions.
In order to further increase the storing capacity, that is, the recording density of the DTM, the magnetic layer in which information is recorded must have a characteristic different from that of a conventional vertical magnetic recording media. The magnetic layer must have a large magnetic anisotropy and a small grain size. However, a material having a large magnetic anisotropy, that is, a high coercivity, may not be recorded using a conventional magnetic head. In this case, a magnetic head that may apply a high magnetic field so as to inverse the magnetization of a magnetic layer having high coercivity must be used. However, in order to increase the magnetic field to a maximum level in a magnetic head, the structure and material of the magnetic head must be modified.